In the past, a power supply device that drives an LED element as a load converts an alternating-current voltage of an alternating-current power supply into a direct-current voltage and outputs the direct-current voltage to between both ends of the LED element to light the LED element.
In such a power supply device that drives the LED element as the load, there is a demand for improvement of a power factor for the purpose of reducing a power capacity (VA). A power supply device adopting, for example, a power supply circuit of a flyback type is proposed in order to obtain a high power factor. However, components of the power supply device are increased in size.
Therefore, the power supply device in the past is increase in size to obtain a high power factor.
There is a demand for a power supply device that is small in size and can obtain a high power factor.